The invention is directed to a semiconductor component having a semiconductor body with a lightly doped middle zone, a more highly doped outer zone of a first conductivity type adjacent thereto, and shorts between the outer zone and zones of second conductivity type arranged in the outer zone adjoining the surface of the semiconductor body.
Such shorts are often indispensable for the function of thyristors. In symmetrical thyristors they are arranged at the cathode side; in GTO thyristors, they are arranged at the anode side. Shorts at the cathode side have also been disclosed in conjunction with power diodes (DE-25 06 102 and "Japan Annuals Reviews in Electronics, Computers and Telecommunications 13, (1984), pages 75 through 87, both incorporated herein by reference).
An optimally low storage charge in the semiconductor component is desirable for use in power converters and choppers. It is known to reduce the storage charge by driving in metals. The drive-in of metals leads to a general shortening of the carrier life time in the lightly doped middle zone, which is flooded by both types of charge carriers. This leads to a pronounced "sag" of the charge carrier concentration in the semiconductor body.
It can be more meaningful for certain applications to diminish the concentration of the charge carriers by deteriorating the emitter efficiency. This is utilized in GTO thyristors in such fashion that the shorts are arranged at the anode side. They are arranged at the anode side so that only a few charge carriers are present from the very outset in the proximity of the emitter at the anode side. The shorts at the anode side in the GTO thyristor are constructed in a way similar to the shorts at the cathode side in the symmetrical thyristor. Since the lightly doped n-base is usually shorted, the short-circuit regions are usually considerably larger than in a thyristor shorted at the cathode side.